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A143373 Expansion of x/(1 - x - 2*x^3 - 2*x^5 - x^7). 5

%I #21 Feb 09 2021 02:31:25

%S 1,1,1,3,5,9,17,30,55,100,181,330,599,1088,1978,3593,6529,11864,21556,

%T 39169,71171,129319,234978,426961,775801,1409655,2561384,4654113,

%U 8456664,15366012,27920509

%N Expansion of x/(1 - x - 2*x^3 - 2*x^5 - x^7).

%D Claude Shannon and Warren Weaver, A Mathematical Theory of Communication, University of Illinois Press, Chicago, 1963, pp. 37-38.

%H G. C. Greubel, <a href="/A143373/b143373.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,2,0,2,0,1).

%t Rest@CoefficientList[Series[x/(1 -x -2*x^3 -2*x^5 -x^7), {x, 0, 40}], x]

%o (PARI) my(x='x+O('x^40)); Vec(x/(1-x-2*x^3-2*x^5-x^7)) \\ _G. C. Greubel_, Sep 27 2017

%o (Sage)

%o def A143373_list(prec):

%o P.<x> = PowerSeriesRing(ZZ, prec)

%o return P( x/(1 -x -2*x^3 -2*x^5 -x^7) ).list()

%o a=A143373_list(40); a[1:] # _G. C. Greubel_, Feb 08 2021

%o (Magma)

%o R<x>:=PowerSeriesRing(Rationals(), 40);

%o Coefficients(R!( x/(1 -x -2*x^3 -2*x^5 -x^7) )); // _G. C. Greubel_, Feb 08 2021

%Y Cf. A122762, A143351, A143372, A143375.

%K nonn,easy

%O 1,4

%A _Roger L. Bagula_ and _Gary W. Adamson_, Oct 22 2008

%E Edited by _G. C. Greubel_, Feb 08 2021

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Last modified March 28 14:13 EDT 2024. Contains 371254 sequences. (Running on oeis4.)